Cervical collars are used in the treatment, stabilization, immobilization, and therapy of cervical trauma. Since cervical spinal injuries are often accompanied by severe head trauma, the first response is often to immobilize the neck (columna cervicalis; cervical vertebral/spinal column). For example, some collars are intended to provide support for whiplash and other such injuries where support for the head and neck is needed. Other collars are intended for near complete immobilization of the head and neck, such as in an EMS (Emergency Medical Services) pre-hospital setting. The immobilization is done to prevent further damage in waiting for subsequent surgical operation or treatment; sometimes, however, the immobilization is used as a final treatment of spinal injuries.
In such an EMS pre-hospital setting, which typically involves vehicular accident victims or others who have suffered head trauma, victims are also at a substantial risk of having a cervical spine injury (“Effect of cervical hard collar on intracranial pressure after head injury,” ANZ J Surg 2002 June; 56(6):511-3; Mobbs et al.). In such cases, a rigid cervical collar can be applied until it is determined that there is no underlying cervical spine injury (id.).
Thus, it is recognized that spinal immobilization can be achieved by the application of a rigid collar to protect the neck and forms an integral part of care of the injured. However, patients with combined head and neck injuries often have higher intracranial pressure (ICP) that may be caused by intracranial hemorrhage and or contusion of the brain.
Intracranial pressure is a dangerous condition, and a number of studies have shown that the use of rigid cervical collars can actually raise intracranial pressure. In particular, the very nature of rigid cervical collar designs predisposes to vascular obstruction of blood draining from the brain, which theoretically may lead to an increase in intracranial pressure.
In fact, some current types of rigid cervical collars are known to provide an increase in pressure on neck veins (vena jugularis externa and interna; external and internal jugular veins) thereby causing stasis in the veins and leading to an increase intracranial pressure. An increase in intracranial pressure deceases cerebral perfusion and exacerbates ischemia, and thus can lead to an increase in the chances for a secondary brain injury can occur (“The effect of rigid cervical collars on internal jugular vein dimensions,” Acad Emerg Med; January 2010, Vol. 17, No. 100-102; Stone et al.).
This suggests that in patients having head injuries, when a rigid collar is used to stabilize the cervical spinal column, the rigid collar should be removed as soon as cervical spine injury has been ruled out.
There is an apparent need then for a short and long term use cervical collar that does not obstruct the blood drain from the brain.